To what extent are CO2 emissions from intra-urban shopping trips by cars affected by drivers’ travel behaviour and store location?

Transportation is seen as one of the major sources of CO2 pollutants nowadays. The impact of increased transport in retailing should not be underestimated. Most previous studies have focused on transportation and underlying trips, in general, while very few studies have addressed the specific affects that, for instance, intra-city shopping trips generate. Furthermore, most of the existing methods used to estimate emission are based on macro-data designed to generate national or regional inventory projections. There is a lack of studies using micro-data based methods that are able to distinguish between driver behaviour and the locational effects induced by shopping trips, which is an important precondition for energy efficient urban planning. The aim of this study is to implement a micro-data method to estimate and compare CO2 emission induced by intra-urban car travelling to a retail destination of durable goods (DG), and non-durable goods (NDG). We estimate the emissions from aspects of travel behaviour and store location. The study is conducted by means of a case study in the city of Borlänge, where GPS tracking data on intra-urban car travel is collected from 250 households. We find that a behavioural change during a trip towards a CO2 optimal travelling by car has the potential to decrease emission to 36% (DG), and to 25% (NDG) of the emissions induced by car-travelling shopping trips today. There is also a potential of reducing CO2 emissions induced by intra-urban shopping trips due to poor location by 54%, and if the consumer selected the closest of 8 existing stores, the CO2 emissions would be reduced by 37% of the current emission induced by NDG shopping trips.

The Optimal trigger speed of vehicle activated signs

The thesis aims to elaborate on the optimum trigger speed for Vehicle Activated Signs (VAS) and to study the effectiveness of VAS trigger speed on drivers’ behaviour. Vehicle activated signs (VAS) are speed warning signs that are activated by individual vehicle when the driver exceeds a speed threshold. The threshold, which triggers the VAS, is commonly based on a driver speed, and accordingly, is called a trigger speed. At present, the trigger speed activating the VAS is usually set to a constant value and does not consider the fact that an optimal trigger speed might exist. The optimal trigger speed significantly impacts driver behaviour. In order to be able to fulfil the aims of this thesis, systematic vehicle speed data were collected from field experiments that utilized Doppler radar. Further calibration methods for the radar used in the experiment have been developed and evaluated to provide accurate data for the experiment. The calibration method was bidirectional; consisting of data cleaning and data reconstruction. The data cleaning calibration had a superior performance than the calibration based on the reconstructed data. To study the effectiveness of trigger speed on driver behaviour, the collected data were analysed by both descriptive and inferential statistics. Both descriptive and inferential statistics showed that the change in trigger speed had an effect on vehicle mean speed and on vehicle standard deviation of the mean speed. When the trigger speed was set near the speed limit, the standard deviation was high. Therefore, the choice of trigger speed cannot be based solely on the speed limit at the proposed VAS location. The optimal trigger speeds for VAS were not considered in previous studies. As well, the relationship between the trigger value and its consequences under different conditions were not clearly stated. The finding from this thesis is that the optimal trigger speed should be primarily based on lowering the standard deviation rather than lowering the mean speed of vehicles. Furthermore, the optimal trigger speed should be set near the 85th percentile speed, with the goal of lowering the standard deviation.

A data driven approach for automating vehicle activated signs

Vehicle activated signs (VAS) display a warning message when drivers exceed a particular threshold. VAS are often installed on local roads to display a warning message depending on the speed of the approaching vehicles. VAS are usually powered by electricity; however, battery and solar powered VAS are also commonplace. This thesis investigated devel-opment of an automatic trigger speed of vehicle activated signs in order to influence driver behaviour, the effect of which has been measured in terms of reduced mean speed and low standard deviation. A comprehen-sive understanding of the effectiveness of the trigger speed of the VAS on driver behaviour was established by systematically collecting data. Specif-ically, data on time of day, speed, length and direction of the vehicle have been collected for the purpose, using Doppler radar installed at the road. A data driven calibration method for the radar used in the experiment has also been developed and evaluated. Results indicate that trigger speed of the VAS had variable effect on driv-ers’ speed at different sites and at different times of the day. It is evident that the optimal trigger speed should be set near the 85th percentile speed, to be able to lower the standard deviation. In the case of battery and solar powered VAS, trigger speeds between the 50th and 85th per-centile offered the best compromise between safety and power consump-tion. Results also indicate that different classes of vehicles report differ-ences in mean speed and standard deviation; on a highway, the mean speed of cars differs slightly from the mean speed of trucks, whereas a significant difference was observed between the classes of vehicles on lo-cal roads. A differential trigger speed was therefore investigated for the sake of completion. A data driven approach using Random forest was found to be appropriate in predicting trigger speeds respective to types of vehicles and traffic conditions. The fact that the predicted trigger speed was found to be consistently around the 85th percentile speed justifies the choice of the automatic model.

Who Should do What to Whom? : Occupational Groups´Views on Special Needs

The overall aim of this thesis is to increase our knowledge of different occupational groups´ views on work with children in need of special support. This is explored in four separate studies. The first study investigates the views of occupational groups in preschools and schools in one municipality. A questionnaire was handed out to all personnel (N=1297) in the municipality in 2008 (72.5 % response rate). The second study explores the views of educational leaders (N=45) in the same municipality. Questionnaire # 2 was distributed in 2009. All the educational leaders responded to the questionnaire. The third study describes the views of different occupational groups concerning special educational needs coordinators´ (SENCOs) role and work. This was highlighted by comparing responses from questionnaire #1 and # 2. Responses concerning SENCOs´ work were also added using a third questionnaire. This questionnaire was handed out in 2006 to chief education officers (N=290) in all municipalities in Sweden. The response rate was 90.3%. Finally, the fourth study presents five head teachers´ descriptions of their work with special needs issues. Study four was a follow-up study of questionnaire # 2. These head teachers were selected because of their inclusive values and because they seemed to be effective according to certain criteria. They were interviewed in January 2012. The results reveal a number of interesting findings. For example, there are both similar and different views among the occupational groups concerning work with children in need of special support. A majority of the respondents in all groups state that children´s individual deficiencies is one common reason why children need special support in preschools/schools. Differences between the occupational groups become especially visible regarding their views of SENCOs‟ work. Critical pragmatism (Cherryholmes, 1988) is applied as a theoretical point of departure. Skrtic´s (1991) critical reading and analysis of special education relative to general education is specifically used to interpret and discuss the outcome of the studies. Additionally, Abbott´s (1988) reasoning concerning the “division of expert labor” is used to discuss the occupational groups´ replies concerning “who should do what to whom”. The findings in the studies are contextualized and theoretically interpreted in the separate articles. However in the first part of this thesis (in Swedish: Kappa), the theoretical interpretations of the empirical outcome are discussed in more detail and the results are further contextualized and synthesised. Inclusion and premises for inclusive education are also discussed in more depth in the first part of the present thesis.

Young peoples’ entrance to the workplace : Introduction to occupational health and safety

Negative outcomes of a poor work environment are more frequent among young workers. The aim of the current study was to study former pupils’ conditions concerning occupational health and safety by investigating the workplaces’, safety climate, the degree of implementation of SWEM and the their introduction programs. Four branches were included in the study: Industrial, Restaurant, Transport and Handicraft, specialising in wood. Semi-structured dialogues were undertaken with 15 employers at companies in which former pupils were employed. They also answered a questionnaire about SWEM. Former pupils and experienced employees were upon the same occasion asked to fill in a questionnaire about safety climate at the workplace. Workplace introduction programs varied and were strongly linked to company size. Most of the former pupils and experienced employees rated the safety climate at their company as high, or good. Employers in three of the branches rated the SWEM implemented at their workplaces to be effective. The Industry companies, which had the largest workplaces, gave the most systematic and workplace introduction for new employees. There are no results from this study explaining the fact that young workers have a higher risk for workplace accidents.